This video, found via PetaPixel, is by Dylan Bennett, who says,
This video explains the f-stop scale used in photography and video. It explains what f-stop actually is and why the f-stop numbers are what they are. I also give an easy trick for remember the entire f-stop scale.
Dylan has some other videos explaining photographic concepts so be sure to visit his channel and see the others once you’ve watched this one.
Helderberg Photographic Society 